The NYPD said at the time the landing gear was found after surveyors hired by the property owner inspecting the rear of 51 Park Place called police on Wednesday.

When plans for the Islamic center at 51 Park Place were made public in 2010, opponents said they didn't want a mosque so close to where Islamic extremists attacked. They argued the site was "sacred" because landing gear from one of the hijacked Boeing 767 jets had punctured the roof of the building on Sept. 11.

During street protests, they clashed with supporters of the center, who said it would promote harmony between Muslims and followers of other faiths.